WASHINGTON – As the Trump administration backs away from legally defending access to health insurance for people with pre-existing medical conditions, congressional candidates in Minnesota are getting ready for another campaign season likely to be dominated by the health care debate.

Republican lawmakers have twice failed to repeal and replace the Affordable Care Act (ACA), while an increasing number of Democrats are advocating for single-payer health care — a difficult proposition even if they win back control of Congress in November. An NBC News-Wall Street Journal poll in early June found more than one in five voters named health care as their top concern in the upcoming midterm elections, more than any other issue.

This month, the Justice Department threw a new twist into the debate when it urged a federal court to get rid of the ACA’s pre-existing conditions protections as part of a lawsuit filed by Texas and 19 other states alleging that the individual mandate is unconstitutional. Attempts by the Republican administration to undercut the ACA — even popular provisions like those protections — could leave some Republicans on the defensive.

“Rep. [Erik] Paulsen has long supported protections for individuals with pre-existing conditions, and he continues to do so,” a spokesman for Paulsen, the Republican representing Minnesota’s Third Congressional District, said in a statement. Paulsen declined an interview request.

Paulsen and his two fellow Minnesota Republicans in Congress voted more than once to repeal and replace the ACA. His DFL opponent, businessman Dean Phillips, is homing in on the issue in a suburban congressional district that went for Democrat Hillary Clinton in 2016.

“The Affordable Care Act is imperfect, but it can be much more successful by investing in it and fixing it,” Phillips said. Pointing to Paulsen’s votes to repeal it, Phillips said he was “disappointed in Erik Paulsen’s continuous efforts to undermine it ... without any thoughtful replacement.”

He added: “I do believe it’s the responsibility for thoughtful Republicans and Democrats to speak against the Justice Department’s actions to stop enforcing the pre-existing condition policy, because it hurts human beings.”

The ACA prevents insurers from denying people coverage, or charging them more, due to pre-existing health problems — perhaps the most popular part of the law. But the plaintiffs in the latest challenge argued that after the Republican tax code overhaul repealed the ACA’s individual mandate penalty, that provision and the entire law are unconstitutional; the Supreme Court in 2012 had claimed it was constitutional under the government’s right to taxation.

Rep. Jason Lewis, a Republican freshman who voted for the tax bill, said the clause about pre-existing conditions has to stay. But he agrees with the administration’s legal rationale: “You cannot justify it under a tax and spending clause.”

“Everyone knows where I am — I voted to reform health care and I’m willing to stand up and [say] that was the right thing to do,” Lewis said. “The Affordable Care Act is in a free fall, so let’s have a debate on that.”

Lewis said that since the ACA is still law, and until the court case is done, those mandates will drive up insurance costs.

That legislation “is still dysfunctional and it’s still a mess, which is why so many Democrats are trying to push for Medicare for all,” Lewis said. He pointed to a recent report from Medicare trustees that the system will be depleted by 2026.

On Thursday, Lewis and Republicans on the House Budget Committee voted for a new budget proposal that would make large cuts to Medicare and Medicaid as part of broader efforts to reduce spending and address the national debt.

“We have to go back to real health care reform that allows people to buy the policy they want, that undoes the price control, so that the health insurance industry can reward people for staying in shape and subsidize risk that way instead of trying to basically socialize medicine,” Lewis said.

DFLer Angie Craig, who’s challenging Lewis, said that 51 percent of non-elderly people in the Second Congressional District have pre-existing conditions.

“This will give insurance companies all the power again to deny people coverage,” Craig said.

“This action by the Trump administration only adds uncertainty and higher costs for Americans,” Craig said. “When the administration does something that will harm voters and people in the district, it is our responsibility as a member of Congress to speak out and speak up, and he’s complicit in his silence.”

Lewis, she said, and other Republicans “have come up with nothing that would fix a broken health care system in the time that they have been in Washington.” Unlike some other Democratic candidates, Craig said she does not endorse the single-payer proposal as outlined by some House Democrats. She supports a high-risk reinsurance program at the federal level, her campaign said, and wants to allow consumers to buy into Medicare to compete with large insurance companies along with addressing prescription drug pricing by allowing reimportation from Canada.

U.S. Rep. Tom Emmer, a Republican who represents the more solidly Republican-leaning Sixth District, did not provide an interview or statement on the administration’s actions on pre-existing conditions.

Emmer’s DFL challenger, Ian Todd, is advocating for a single-payer health care system. He said he was surprised to find even some conservative voters were open to his views. People know the current system isn’t working, he added.

“Do I think I’ll have most conservatives come over to my side? No, I don’t,” said Todd. “But there are a lot of people who do see things from my point of view that I wouldn’t have expected.”

He said he would talk about Emmer’s votes to repeal and replace the ACA during the campaign, but that “it’s less about what he’s done and more about what we can do” in the future.